I'd love to have been able to buy an IS200 for that sort of money. I'd be putiing a 1UZ into it and then add turbos! :)
If you're buying an engine of the same type, you shouldn't need the ECU as well but most sellers lump it all together as a package (engine, loom and ECU). It's never a bad thing to have a spare ECU anyway if this were the case.
If your car is manual, you'll need an ECU for a manual - if it is auto, you need the Auto ECU. Auto ECUs generally work on a manual with some wiring mods (although personally I'd still just use the suitable ECU to keep it straightforward) but the manual ECU will not work on an Auto.